<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        function fn() {
            console.log(this)
        }
        fn()
        var o = {
            name:"zs",
            age:19
        }
        var fn1 = function fn() {
                    console.log(this)
                }.bind(o)
        fn1()
        </script>
</body>
</html>